1. Technical Field
The present invention relates to a printing roll to form minute patterns in liquid crystal display (LCD) devices and semiconductor devices, and more particularly, to a blanket being adhered to the printing roll.
2. Discussion of the Related Art
Generally, LCD devices and semiconductor devices are provided with a plurality of layers patterned on a substrate. Accordingly, various processes are performed to pattern the plurality of layers. In order to pattern the plurality of layers in various shapes, it is necessary to perform photolithography.
The photolithography necessarily uses a mask having a predetermined pattern and a light-irradiation apparatus, so that the manufacturing cost increases. In addition, since the photolithography requires exposure and development, it complicates the patterning process and increases manufacturing time.
To overcome these problems of photolithography, a new patterning method has been developed, for example, a printing method using a printing roll.
FIGS. 1A to 1C are views illustrating a patterning method using a related art printing roll.
First, as shown in FIG. 1A, a pattern material 20 is applied to a printing roll 30 on which a blanket 35 is adhered through a printing nozzle 10. Thus, the surface of printing roll 30 is coated with the pattern material 20. In this case, the pattern material 20 is mixed with a volatile solvent. The volatile solvent makes smooth the application of the pattern material 20 coated on the printing roll 30. Just after coating the printing roll 30 with the pattern material 20, the volatile solvent is vaporized.
After that, as shown in FIG. 1B, the printing roll 30 is rotated on a printing plate 40 provided with a plurality of protrusions 20b. As a result, some of the pattern material is transferred to the protrusions of the printing plate 40, and the remaining pattern material 20a forms a predetermined pattern on the printing roll 30.
Referring to FIG. 1C, the printing roll 30 is rotated on a substrate 50, whereby the remaining pattern material 20a of the printing roll 30 is transferred to the substrate 50, thereby forming the desired pattern on the substrate 50.
The blanket 35 requires good adherence to the printing roll 30, and also requires anti-deformation properties to resist deformation during the printing process. In this respect, the blanket 35 is generally formed of an Si-based resin. However, the Si-based resin is weakened by permeation of the volatile solvent which melts the pattern material 20. Thus, the blanket 35 of Si-based resin may be deformed due to permeation of the volatile solvent. If the blanket 35 is deformed, it is difficult to smoothly perform the coating and printing process, so that the formed pattern is not precise.